I also want lighting that fits in the fixtures that I have and doesn't protrude beyond the shade. Almost all of these "better lightbulbs" are just too large. Also why make intelligent light bulbs? Wouldn't it be better to put the connectivity into the light fixture, especially if it has more than one bulb?

Agreed, as long as the mechanical properties of the printed material are suitable for the part being replaced. For most metal parts, traditional machining is more economical. Trying to replicate traditional manufacturing processes is a dead end IMHO. These processes were optimized over the last 4000 years, at least since the bronze age.

OTOH, 3D printing is really interesting because it allows the creation of new types of structures such as hollow parts with complicated internal geometries. Such structures cannot be made (easily) by any traditional forming processes. - That's actually the direction where I think 3D printing could become the next big thing; ulltra-reliable machines that cannot be assembled or disassembled. Printing a 3D gun and assembling it out of discrete parts is dumb. To get this old crank really excited, somebody would have to print a working mechanical watch, right out of the printer.

Structural plastic developer here, three years of professional experience in this area. The problem from a purely structural standpoint is that 3d printing cannot print fibre-reinforced plastics. There has been some preliminary work on this at the Frauenhofer Institut in Stuttgart, Germany. http://www.ipa.fraunhofer.de/ Their solution is running a nylon thread through the printer nozzle. For this, they have a spool of thread and a mechanism similar to a sewing machine on the printer head. This creates a part with a continuous thread that is oriented in the raster pattern traveled by the printer head. But the part does not have the characteristics of an injection-molded fibre-reinforced part, which would have many small fibers with many various orientations. I visited the site personally and saw their research first hand. They still have some technological problems to work out. For example, I don't think they understand shrinkage fully and would have a hard time complying with engineering tolerances. But for a quick prototype, more than adequate. Prototypes can be made to fit. ;-)

I won't go into material cost. Any industrial 3D printing outfit, that's halfway serious about what they do, would use raw granulate and not buy cartridges. But the main short coming of 3D printing as opposed to injection molding in a production environment is the cycle time. A complex part with tight tolerances (TG 3 after DIN 16742) of around 100-200 Gramms in an fibre-reinforced PA6 or PA12 can be injection molded in about two to three minutes, depending on injection temperature and cooling time in the mold, etc. The actual injection time is around one second for a reference. Otherwise material hardens during the injection process. The time required to print the same part would be many hours or even a day or more, depending on the printer used. I was at a 3D outfit and showed them a simple part of less than 10 Gramms. It would have taken in their estimation 30 minutes to print. Not good for mass production.

Where 3D printing is actually useful is generating rapid 3D prototypes or for doing custom parts in non-reinforced plastics. But custom parts, if they do wind up in the hands of a customer, aren't of good enough quality for my company to sell without hand-finishing to at least simulate the surface finish and texture of an injection-molded part. Acetone can be used here to make a smooth surface finish. Costs are high, but less than the cost of making a mold for a one-of-a-kind part. Alternatively custom parts can be made the old-fashioned way, that is by hand.

Usually the marketing people want the 3D parts more than the developers. Sometimes we use printed parts in development prototypes for parts where we haven't gotten around to making a prototype mold for. But these parts have limits, they usually cost a lot and if I need a high two digit or a three-digit-quantity, it's usually much cheaper to make a prototype mold. But sometimes it's difficult to convince management of that, which is probably a common problem. But after a couple of projects, the management's starting to come around to my point of view on this.

I thought you were going to say they would print gold bars!!! But wait, then you would need gold to print gold. We've got a conundrum...

Proving once again that NASA hasn't quite gotten out of the '80s yet.

If someone dropped a vintage Hasselblad camera in my back yard and left, I wouldn't be one to complain.

A good alternative to chemical bonding of plastics is ultrasonic welding.

Crimean Special Election Ballot (English Translation):
1. Mark Here_____ if you want to be an notionally 'independent' country that is in a slowly decaying orbit around mother Russia.
2. Mark Here_____ if you really really really want to join Russia now!!!

For as long as Putin and his cronies are in power, the U.S. and the rest of the western world should offer any law-abiding Russian citizen who wants to leave an automatic green card, work permit, etc. We cannot realistically or morally change Russia from the outside. The most powerful weapon against fanaticism would be allowing regular law-abiding Russians to vote with their feet. We could always use some more scientists and engineers anyway...

I did the exact same thing, the last time I bought a new car. (It's been a while) The only harassment was when the "manager" tried to hard sell me a "rust protective coating" and an "electrolytic rust protection" system for around $500 each. I figured I could get those things for less somewhere else. After about ten minutes, he gave up. Later on, did an internet search for both "options" and realized they were just scams to skim off an extra few dollars on top of the deal. The electrolytic system only "works" if the auto were submerged in salt water, something I don't plan on doing. It's not a boat. Glad I said no.

and you can't repeal demographics. The last time the Republicans made this argument, they forgot that their most reliable voting block was retired white males over the age of 65.

It's almost as good as Putin's quote about "local security forces" buying Russian uniforms at any local military surplus store. So in order to protect law and order in my own country, I'm supposed to don the uniform of a foreign country? Now where did I put that old French Foreign Legion ensemble?

Sounds like something out of Superman 3.

"Remember, you must think in Russian..."

Tanks, but no tanks.